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Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/fs/minix/bitmap.c | |
4 | * | |
5 | * Copyright (C) 1991, 1992 Linus Torvalds | |
6 | */ | |
7 | ||
8 | /* | |
9 | * Modified for 680x0 by Hamish Macdonald | |
10 | * Fixed for 680x0 by Andreas Schwab | |
11 | */ | |
12 | ||
13 | /* bitmap.c contains the code that handles the inode and block bitmaps */ | |
14 | ||
15 | #include "minix.h" | |
1da177e4 LT |
16 | #include <linux/buffer_head.h> |
17 | #include <linux/bitops.h> | |
e8edc6e0 | 18 | #include <linux/sched.h> |
1da177e4 | 19 | |
cc46759a AV |
20 | static DEFINE_SPINLOCK(bitmap_lock); |
21 | ||
f1fd306a AV |
22 | /* |
23 | * bitmap consists of blocks filled with 16bit words | |
24 | * bit set == busy, bit clear == free | |
25 | * endianness is a mess, but for counting zero bits it really doesn't matter... | |
26 | */ | |
27 | static __u32 count_free(struct buffer_head *map[], unsigned blocksize, __u32 numbits) | |
1da177e4 | 28 | { |
f1fd306a AV |
29 | __u32 sum = 0; |
30 | unsigned blocks = DIV_ROUND_UP(numbits, blocksize * 8); | |
1da177e4 | 31 | |
f1fd306a AV |
32 | while (blocks--) { |
33 | unsigned words = blocksize / 2; | |
34 | __u16 *p = (__u16 *)(*map++)->b_data; | |
35 | while (words--) | |
36 | sum += 16 - hweight16(*p++); | |
1da177e4 LT |
37 | } |
38 | ||
f1fd306a | 39 | return sum; |
1da177e4 LT |
40 | } |
41 | ||
939b00df | 42 | void minix_free_block(struct inode *inode, unsigned long block) |
1da177e4 | 43 | { |
939b00df AB |
44 | struct super_block *sb = inode->i_sb; |
45 | struct minix_sb_info *sbi = minix_sb(sb); | |
46 | struct buffer_head *bh; | |
47 | int k = sb->s_blocksize_bits + 3; | |
48 | unsigned long bit, zone; | |
1da177e4 LT |
49 | |
50 | if (block < sbi->s_firstdatazone || block >= sbi->s_nzones) { | |
11b84487 | 51 | printk("Trying to free block not in datazone\n"); |
1da177e4 LT |
52 | return; |
53 | } | |
54 | zone = block - sbi->s_firstdatazone + 1; | |
939b00df AB |
55 | bit = zone & ((1<<k) - 1); |
56 | zone >>= k; | |
1da177e4 LT |
57 | if (zone >= sbi->s_zmap_blocks) { |
58 | printk("minix_free_block: nonexistent bitmap buffer\n"); | |
59 | return; | |
60 | } | |
61 | bh = sbi->s_zmap[zone]; | |
cc46759a | 62 | spin_lock(&bitmap_lock); |
939b00df AB |
63 | if (!minix_test_and_clear_bit(bit, bh->b_data)) |
64 | printk("minix_free_block (%s:%lu): bit already cleared\n", | |
1da177e4 | 65 | sb->s_id, block); |
cc46759a | 66 | spin_unlock(&bitmap_lock); |
1da177e4 LT |
67 | mark_buffer_dirty(bh); |
68 | return; | |
69 | } | |
70 | ||
71 | int minix_new_block(struct inode * inode) | |
72 | { | |
73 | struct minix_sb_info *sbi = minix_sb(inode->i_sb); | |
939b00df | 74 | int bits_per_zone = 8 * inode->i_sb->s_blocksize; |
1da177e4 LT |
75 | int i; |
76 | ||
77 | for (i = 0; i < sbi->s_zmap_blocks; i++) { | |
78 | struct buffer_head *bh = sbi->s_zmap[i]; | |
79 | int j; | |
80 | ||
cc46759a | 81 | spin_lock(&bitmap_lock); |
939b00df AB |
82 | j = minix_find_first_zero_bit(bh->b_data, bits_per_zone); |
83 | if (j < bits_per_zone) { | |
84 | minix_set_bit(j, bh->b_data); | |
cc46759a | 85 | spin_unlock(&bitmap_lock); |
1da177e4 | 86 | mark_buffer_dirty(bh); |
939b00df | 87 | j += i * bits_per_zone + sbi->s_firstdatazone-1; |
1da177e4 LT |
88 | if (j < sbi->s_firstdatazone || j >= sbi->s_nzones) |
89 | break; | |
90 | return j; | |
91 | } | |
cc46759a | 92 | spin_unlock(&bitmap_lock); |
1da177e4 LT |
93 | } |
94 | return 0; | |
95 | } | |
96 | ||
016e8d44 | 97 | unsigned long minix_count_free_blocks(struct super_block *sb) |
1da177e4 | 98 | { |
016e8d44 | 99 | struct minix_sb_info *sbi = minix_sb(sb); |
6d6747f8 | 100 | u32 bits = sbi->s_nzones - sbi->s_firstdatazone + 1; |
016e8d44 JB |
101 | |
102 | return (count_free(sbi->s_zmap, sb->s_blocksize, bits) | |
1da177e4 LT |
103 | << sbi->s_log_zone_size); |
104 | } | |
105 | ||
106 | struct minix_inode * | |
107 | minix_V1_raw_inode(struct super_block *sb, ino_t ino, struct buffer_head **bh) | |
108 | { | |
109 | int block; | |
110 | struct minix_sb_info *sbi = minix_sb(sb); | |
111 | struct minix_inode *p; | |
112 | ||
113 | if (!ino || ino > sbi->s_ninodes) { | |
114 | printk("Bad inode number on dev %s: %ld is out of range\n", | |
115 | sb->s_id, (long)ino); | |
116 | return NULL; | |
117 | } | |
118 | ino--; | |
119 | block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks + | |
120 | ino / MINIX_INODES_PER_BLOCK; | |
121 | *bh = sb_bread(sb, block); | |
122 | if (!*bh) { | |
11b84487 | 123 | printk("Unable to read inode block\n"); |
1da177e4 LT |
124 | return NULL; |
125 | } | |
126 | p = (void *)(*bh)->b_data; | |
127 | return p + ino % MINIX_INODES_PER_BLOCK; | |
128 | } | |
129 | ||
130 | struct minix2_inode * | |
131 | minix_V2_raw_inode(struct super_block *sb, ino_t ino, struct buffer_head **bh) | |
132 | { | |
133 | int block; | |
134 | struct minix_sb_info *sbi = minix_sb(sb); | |
135 | struct minix2_inode *p; | |
939b00df | 136 | int minix2_inodes_per_block = sb->s_blocksize / sizeof(struct minix2_inode); |
1da177e4 LT |
137 | |
138 | *bh = NULL; | |
139 | if (!ino || ino > sbi->s_ninodes) { | |
140 | printk("Bad inode number on dev %s: %ld is out of range\n", | |
141 | sb->s_id, (long)ino); | |
142 | return NULL; | |
143 | } | |
144 | ino--; | |
145 | block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks + | |
939b00df | 146 | ino / minix2_inodes_per_block; |
1da177e4 LT |
147 | *bh = sb_bread(sb, block); |
148 | if (!*bh) { | |
11b84487 | 149 | printk("Unable to read inode block\n"); |
1da177e4 LT |
150 | return NULL; |
151 | } | |
152 | p = (void *)(*bh)->b_data; | |
939b00df | 153 | return p + ino % minix2_inodes_per_block; |
1da177e4 LT |
154 | } |
155 | ||
156 | /* Clear the link count and mode of a deleted inode on disk. */ | |
157 | ||
158 | static void minix_clear_inode(struct inode *inode) | |
159 | { | |
160 | struct buffer_head *bh = NULL; | |
161 | ||
162 | if (INODE_VERSION(inode) == MINIX_V1) { | |
163 | struct minix_inode *raw_inode; | |
164 | raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh); | |
165 | if (raw_inode) { | |
166 | raw_inode->i_nlinks = 0; | |
167 | raw_inode->i_mode = 0; | |
168 | } | |
169 | } else { | |
170 | struct minix2_inode *raw_inode; | |
171 | raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh); | |
172 | if (raw_inode) { | |
173 | raw_inode->i_nlinks = 0; | |
174 | raw_inode->i_mode = 0; | |
175 | } | |
176 | } | |
177 | if (bh) { | |
178 | mark_buffer_dirty(bh); | |
179 | brelse (bh); | |
180 | } | |
181 | } | |
182 | ||
183 | void minix_free_inode(struct inode * inode) | |
184 | { | |
939b00df | 185 | struct super_block *sb = inode->i_sb; |
1da177e4 | 186 | struct minix_sb_info *sbi = minix_sb(inode->i_sb); |
939b00df AB |
187 | struct buffer_head *bh; |
188 | int k = sb->s_blocksize_bits + 3; | |
189 | unsigned long ino, bit; | |
1da177e4 LT |
190 | |
191 | ino = inode->i_ino; | |
192 | if (ino < 1 || ino > sbi->s_ninodes) { | |
193 | printk("minix_free_inode: inode 0 or nonexistent inode\n"); | |
5ccb4a78 | 194 | return; |
1da177e4 | 195 | } |
939b00df AB |
196 | bit = ino & ((1<<k) - 1); |
197 | ino >>= k; | |
198 | if (ino >= sbi->s_imap_blocks) { | |
1da177e4 | 199 | printk("minix_free_inode: nonexistent imap in superblock\n"); |
5ccb4a78 | 200 | return; |
1da177e4 LT |
201 | } |
202 | ||
203 | minix_clear_inode(inode); /* clear on-disk copy */ | |
204 | ||
939b00df | 205 | bh = sbi->s_imap[ino]; |
cc46759a | 206 | spin_lock(&bitmap_lock); |
939b00df AB |
207 | if (!minix_test_and_clear_bit(bit, bh->b_data)) |
208 | printk("minix_free_inode: bit %lu already cleared\n", bit); | |
cc46759a | 209 | spin_unlock(&bitmap_lock); |
1da177e4 | 210 | mark_buffer_dirty(bh); |
1da177e4 LT |
211 | } |
212 | ||
4f45ba3d | 213 | struct inode *minix_new_inode(const struct inode *dir, umode_t mode, int *error) |
1da177e4 LT |
214 | { |
215 | struct super_block *sb = dir->i_sb; | |
216 | struct minix_sb_info *sbi = minix_sb(sb); | |
217 | struct inode *inode = new_inode(sb); | |
218 | struct buffer_head * bh; | |
939b00df AB |
219 | int bits_per_zone = 8 * sb->s_blocksize; |
220 | unsigned long j; | |
221 | int i; | |
1da177e4 LT |
222 | |
223 | if (!inode) { | |
224 | *error = -ENOMEM; | |
225 | return NULL; | |
226 | } | |
939b00df | 227 | j = bits_per_zone; |
1da177e4 LT |
228 | bh = NULL; |
229 | *error = -ENOSPC; | |
cc46759a | 230 | spin_lock(&bitmap_lock); |
1da177e4 LT |
231 | for (i = 0; i < sbi->s_imap_blocks; i++) { |
232 | bh = sbi->s_imap[i]; | |
939b00df AB |
233 | j = minix_find_first_zero_bit(bh->b_data, bits_per_zone); |
234 | if (j < bits_per_zone) | |
1da177e4 LT |
235 | break; |
236 | } | |
939b00df | 237 | if (!bh || j >= bits_per_zone) { |
cc46759a | 238 | spin_unlock(&bitmap_lock); |
1da177e4 LT |
239 | iput(inode); |
240 | return NULL; | |
241 | } | |
939b00df | 242 | if (minix_test_and_set_bit(j, bh->b_data)) { /* shouldn't happen */ |
cc46759a | 243 | spin_unlock(&bitmap_lock); |
939b00df | 244 | printk("minix_new_inode: bit already set\n"); |
1da177e4 LT |
245 | iput(inode); |
246 | return NULL; | |
247 | } | |
cc46759a | 248 | spin_unlock(&bitmap_lock); |
1da177e4 | 249 | mark_buffer_dirty(bh); |
939b00df | 250 | j += i * bits_per_zone; |
1da177e4 LT |
251 | if (!j || j > sbi->s_ninodes) { |
252 | iput(inode); | |
253 | return NULL; | |
254 | } | |
9eed1fb7 | 255 | inode_init_owner(inode, dir, mode); |
1da177e4 | 256 | inode->i_ino = j; |
02027d42 | 257 | inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); |
ba52de12 | 258 | inode->i_blocks = 0; |
1da177e4 LT |
259 | memset(&minix_i(inode)->u, 0, sizeof(minix_i(inode)->u)); |
260 | insert_inode_hash(inode); | |
261 | mark_inode_dirty(inode); | |
262 | ||
263 | *error = 0; | |
264 | return inode; | |
265 | } | |
266 | ||
016e8d44 | 267 | unsigned long minix_count_free_inodes(struct super_block *sb) |
1da177e4 | 268 | { |
016e8d44 JB |
269 | struct minix_sb_info *sbi = minix_sb(sb); |
270 | u32 bits = sbi->s_ninodes + 1; | |
271 | ||
272 | return count_free(sbi->s_imap, sb->s_blocksize, bits); | |
1da177e4 | 273 | } |